riscv: support Allwinner D1 clock controllers

[julien.cassette_gmail.com]

Summary

The CCU controls reset and clocks of most peripherals, so this adds
the definitions needed by the aw_ccung driver to support the D1.

The RTC clock outputs (iosc and osc32k) are needed by the CCU so this
also adds the D1 compatible data to aw_rtc.

Signed-off-by: Julien Cassette <[e-mail]>

Test Plan

The drivers output consistent clock configuration: see https://pastebin.com/9mpYiFqS

[julien.cassette_gmail.com]

Rebase, add commit message